3 foot lengths please

I went to Rona, with my sister, on Saturday. We were putting some stairs on my deck. We picked out the stringers and then went to get the lumber for the steps. I picked out a nice 12 foot 2x10. There are four steps and they needed to be about 3 feet wide. For those that can't multiply that is a total of 12 feet in length. Emily was pondering how this would fit in her truck and since we were standing by the wood cutting centre, I said lets get it cut. First four cuts are free. So we waited until the guy finished helping another gentleman. He came over and I said could you cut this in four pieces for me. He looked down at me like I was totally stupid. So I said "in three foot lengths please". He grabbed my 2x10 and off he went to his saw. He had not said a word to me. I was feeling pretty good though, that was one less step we'd have to do at home and there would be no problem fitting them in the truck. I was quite disappointed when he came back and put the pieces on the cart and they were all different lengths. Then he says, after seeing the stringers, "oh, you probably wanted those in exact lengths". Uh, duh. Emily and I were totally not impressed, being quite capable ourselves of cutting wood to the required length. Being quite annoyed, we said no, that's okay we'll fix it at home. The good part was that 3 feet was only an estimate on my part having forgotten to measure before we went to Rona. A damn good estimate too. The steps on the deck are the width of the shortest length he cut which was approximately 35". I guess I'll have to specify that I want an exact length next time....